A heat spreader (100) includes a metal casing (60) formed by electrodeposition and defining a vapor chamber (40) therein, and a mesh (12b) lining an inner surface of the metal casing. A method for manufacturing the heat spreader includes: providing a core (60a) having a mesh layer (12a) including a plurality of pores and a filling material (14) filled in the pores of the mesh layer and a major space enclosed by the mesh layer; electrodepositing a layer of metal coating (60b) on an outer surface of the core; removing the filling material from the coating layer and the pores of the mesh layer; and filling a working fluid into the coating layer and hermetically sealing the coating layer to thereby obtain the heat spreader with therein a wick structure (12) formed by the mesh layer and the vapor chamber formed by said major space.